1. Field of the Invention
This invention generally relates to antennas and wireless transceivers, and more specifically, to an antenna and a wireless transceiver applicable to wireless communications.
2. Description of Related Art
Antennas are essential to wireless communications. To meet users' demands, antenna circuits have a trend toward small size, high performance, wide bandwidth, high reception quality, etc. as far as technology development is concerned.
To effect high performance and wide bandwidth in a small-sized receiving device, the distance between the receiver and the source of electromagnetic interference is becoming shorter. The electromagnetic interference is unavoidable when the antenna and the circuits are operated concurrently. Since electromagnetic force is generated within different frequencies or a band due to discontinuous or continuous changes in voltage or current, the electromagnetic interference commonly happens while an electronic device or an electronic equipment is operating, and the generated electromagnetic force may interfere with another electronic device by conductor transmission or radiation;
Therefore, designers in the wireless communication industry endeavor to overcome the interference and the noise between various components inside an antenna.
At present, there are some methods for suppressing electromagnetic interference; one of the methods involves using a shield box to cover circuits and suppress electromagnetic interference between the antenna and the circuit, and further electrically connecting the circuits with receiving end of the antenna via a line, thereby enabling the circuits to be disposed in a small-sized receiving device capable of receiving/transmitting wireless electromagnetic signals while operating in a wide bandwidth and high performance surroundings.
For prior art related to application of a shield box for suppressing interference between an antenna and circuits, please refer to Taiwan Patent Publication No. 200715642: “Antenna and Method for Fabricating the Same” and FIG. 1 in the specification of the present invention. An antenna 10 disclosed by Taiwan Patent Publication No. 200715642 comprises a shield plate 11 and an antenna plate 12, wherein a plurality of foldable plates are disposed alongside the shield plate 11, and a shield cover wireless module is formed to function as an electromagnetic shielding cover and system grounding by bending vertically the foldable plates and along with the shield plate 11 and allowing the antenna plate 12 to be connected to the margin of the shield plate 11 so as for the antenna plate 12 and the shield plate 11 to be integral to the antenna 10.
According to application of products complying with IEEE 802.11a/b/g/n standards, a multiple input/output transmission system is required to operate coordinately, and thus there are always more than two antennas in use. However, if any two antennas are too close to each other, severe electromagnetic interference happens, and thus reception quality is compromised. Also, antennas takes up space inside a device, and the antennas may be inefficiently arranged to the detriment of the arrangement of other components inside the device to thereby render the otherwise compact device bulky.
Hence, it is an urgent issue in the industry to provide a technique of avoiding electromagnetic interference otherwise prevalent among two or more antennas positioned closely to one another and avoiding inefficient arrangement of antennas.